Abstract

Background

Previous animal studies have shown that Curcuma (C.) longa lowers plasma glucose. C. longa may thus be a promising ingredient in functional foods aimed at preventing type 2
diabetes. The purpose of the study is to study the effect of C. longa on postprandial plasma glucose, insulin levels and glycemic index (GI) in healthy
subjects.

Methods

Fourteen healthy subjects were assessed in a crossover trial. A standard 75 g oral
glucose tolerance test (OGTT) was administered together with capsules containing a
placebo or C. longa. Finger-prick capillary and venous blood samples were collected before, and 15, 30,
45, 60, 90, and 120 min after the start of the OGTT to measure the glucose and insulin
levels, respectively.

Results

The ingestion of 6 g C. longa had no significant effect on the glucose response. The change in insulin was significantly
higher 30 min (P = 0.03) and 60 min (P = 0.041) after the OGTT including C. longa. The insulin AUCs were also significantly higher after the ingestion of C. longa, 15 (P = 0.048), 30 (P = 0.035), 90 (P = 0.03), and 120 (P = 0.02) minutes after the OGTT.

Conclusions

The ingestion of 6 g C. longa increased postprandial serum insulin levels, but did not seem to affect plasma glucose
levels or GI, in healthy subjects. The results indicate that C. longa may have an effect on insulin secretion.